Introduction to the CohortBeginning in 1994, investigators for the Religious Orders Study (ROS) recruited older Catholic nuns, priests and brothers from across the United States to participate in their longitudinal study of neurologic and cognitive aging. As of June 2007, the ROS had enrolled 1,025 individuals who were free of dementia at baseline evaluation. Enrollment continues. Since enrollment, participants have undergone annual evaluations. At enrollment, members of the cohort were, on average, 75.1 years old; 69% were female.

Ethnicity BreakdownApproximately 89% of the cohort members were white.